One seldom hears the term “Maunder Minimum” even at the most wonkish cocktail parties in the upscale Georgetown or Capitol Hill neighborhoods of Washington, D.C. climate change activists or lobbyists.

Sun minimum - maximum

But random talk of our planet’s soon entering – or perhaps having recently entered – a “new ice age” characterized by global cooling? That’s a different matter: that subject comes up repeatedly among those eager to disprove any significant ongoing atmospheric warming.

So, what’s behind the incessant refrain? And what is the science community’s evidence-based rebuttal? That’s the subject of this month’s Yale Climate Connections “This Is Not Cool” original video.

“Maunder Minimum” refers to a seven-decade-long period from 1645 to 1715 during which the “grand solar minimum” was characterized by extremely rare sunspots. That time coincided with what is known as the “Little Ice Age.” The term comes from the name of British astronomer Edward Walter Maunder, who in 1894 reported the low sunspot activity.

Fewer sunspots at some point? That 'won't get us out of the woods' regarding man-made warming. Click To Tweet

In the new video, Scripps Institution of Oceanography physicist Dan Lubin, PhD, lead author of a recent research report on the issue in Astrophysical Journal Letters, says even a deep plunge into a new solar minimum “won’t get us out of the woods in respect to anthropogenic climate change.”

That view is supported also by solar radiation expert Judith Lean, PhD, of the Naval Research Laboratory.

She points to global surface temperature about 1 degree Centigrade, 1.8 degrees Fahrenheit, warmer now than at the time of the Maunder Minimum and says a return to a Maunder Minimum phenomenon would lead to a cooling by only one-tenth of a degree C or .18 degree F.

“So, we will never get back to a Little Ice Age,” Lean emphasizes. “When people say the Sun is going into a Maunder Minimum, that’s one thing.” But she says it “does not follow” that Earth’s temperature would revert to what it was during the earlier Little Ice Age” period.

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